Photographic printing material



mow- 2911 3. 2.

- production of reflex copies.

UNITED srATss PATENT OFFICE f 2,322,902 f Gottlieb yon Poser, Wieobaden, Germany; vested in the Alien Property Custodian No Drawing. Application January 4, 1941, Serial No. 373,139. In Germany December 27, 1939 150lalms.

and its derivatives, the term fluoreno'nes" means fluorenone and its derivatives; and the term acridones means acridone and its derivatives.

Now I have found that the light-sensitiveness of relatively light-insensitive diazo-compounds may be enhanced when they are combined with aromatic keto-compounds, particularly such as are soluble in water or in a mixture of water and alcohol respectively. Preferably the said ketocompounds should contain more than'one aromatic nucleus, for example two or three aromatic nuclei. Ketmcompounds whichcontain a CO-group in a benzene ring or another ring, for instance quinones have proven particularly good.

diazo-compounds particularly belong to said kind However, also compounds of the benzophenone 01' diam-compounds. The afore-named diazotype are also suitable. It is furthermore desirable compounds are in most cases distinguished by the that the sensitizers be not dyestuffs. They tact thatthe photographic prints prepared thereshould preferably be colorless or only slightly with have only a slight tendency to turn yellow. I colored.

Moreover, they are particularly suitable for the Suitable sensitizers are for instance-anthra- They yield reflex copies very rich in contrast. Furthermore the dyestuffs forming the picture of the reflex copies strongly absorb chemically active light it suitable azo-components are used as this is described in detail in the co-pending U. S. Patent Application Serial No. 276,420 filed May 29, 1939, now U. S. Patent No. 2,246,425 of June 17, 1941. The reflex copies are therefore well suited for being reproduced on photographic printing paper, for instance diazotype paper. In spite of these favorable properties the diam-compounds in question quinone and the derivatives thereof. Such derivatives are especially useful as are readily soluble ilk water. They may be added to the aq eous or aqueous-alcoholic solution containing the dimcompounds on producing the photographicprinting materials. The benzene nuclei of the anthraquinone may carry, for instance, simple substituents, such a alkyl groups, halogen atoms, carboxylic or sulfonic acid groups. Anthraquinone have acquired only very little practical imporprovided that a usual source of light, for instance the arc lamp is employed for the exposure. Also as used herein the term quinones means aromatic keto compounds containing the quinone grouping such as anthraquinone and its derivatives, benzanthrone, naphthoquinone, naphthanthraquinone, and diphenolbenzoquinone; the term phenones" means aromatic keto compounds wherein theketo group is a bridge member, but not apart of a ring system such as benzophenone NaOaS Furthermore, there may for instance be used the 1.2-naphthoquinone-4-sulfonic acid and the fluorenone-2.'7-disulionic acid. Other suitable sensitizers are the sulfonation product of the acridone (produced by introducing acridone into ten times its weight of sulfuric acid monohydrate, heating the whole 'for 1 hour on the vapor bath and precipitating it by the addition of ice water),

the sulfonation product of naphthanthraquinone .(produced by introducing naphthanthraqulnone into ten times its weight of fuming sulfuric acid containing 20 per cent of free S03 and heating the whole for half an hour on the vapor bath). The sulfonation products of benzophenone or of para-chloro-benzophenone are likewise useful. These products may be obtained by heatin benzophenone or para-chloro-benzophenone with six times its weight of turning sulfuric acid containing 20 per cent of free S: to 90 0., adding once its weight of fuming sulfuric acid of 70 per cent SO: and further heating the whole for A hour. The sodium salts of the above-named sulfonation products may be separated from the solutions by the addition of ice-water and caustic soda.

By means of the afore-named sensitizers the light-sensitiveness of relatively light-insensitive diazo-compounds may be enhanced to a multiple so that they then satisfy the practical requirements. Colorless diazo-compounds of the benzene series which are free from amino groups may be sensitized with particularly good success, for example diazo phenols and diazo phenol ethers. Diazo phenol alkyl ethers i. e. the diazotlzation products of p-anisidine, o-anisidine and similar alkyl ethers of amino-phenols are particularly well suitable for the purpose of the invention. Other suitable colorless diazo compound are mentioned in the copending application 276,420. Slightly colored compounds, for instance the tetrazotized 'dianisidine, may, likewise be sensitized.

The proportion of the sensitizers present in the photographic printing material may be just as 1 large as that of the diazo compounds. In general, however, an effect may be produced by an essentially smaller quantity of the sensitizer than that named above. In many cases a few percentages calculated on the diazo-compound. are

, rested particularly well.

The following examples serve to illustrate theinvention, but they are not intended to limit it thereto: v

(1) A foil of regenerated cellulose is bathed in a solution containing in 1000 cc. of water Grams 5-chloro-2-diazobenzene-l-sulfonic acid Tartaric acid 12 Boric acid 7 6 Sodium naphthalene-1.3.6-trisulfonate 20 Sodium 2-naphthol-3.6-disulfonate 8 Sodium 'anthraquinone-2.7-disulfonate- 5 By exposing the dried film for about 1 minute to the light of an arc lamp (18 amperes, distance=40 cm.) under an original and developing it by the treatment with ammonia gas, an orange-red image is obtained. By preparing the film with the same solution while omitting the anthraquinone derivative, 6-7 minuteswould be required for copying the original.

2) A evenness-hydrate an is impregnated with a solution containing in 1000 cc. of water Grams 5-ethoxy-2-diazobenzene-l-sulfonic acid 10 Tartaric acid 15 Boric acid 8 Sodium 2-naphthol-3.6-disulfonate 10 Sodium 2.7-anthraquinone-disulfonate 20 With the'aid of the film thus prepared diazo photographic printing copies may be produced in the usual manner. The light-sensitiveness of the film amounts to about 15 times the light-sensitiveness of a copying material prepared in the samemanner, but without the addition of the anthraquinone-compound.

Instead of the afore-named diazo-compound there may be used with a similar success the 4-diazo-1-anisole, the z-diazo-l-amsole, the 4- diazo-l-phenol, the 2-diazo-5-hydroxybenzene-1- sulfonic acid and the 4-diazo-l-phenoxybenzene.

(3) An acetyl-cellulose film superficially saponified is coated with a solution containing in 1000 cc. of water i The exposure to light of the copying material obtained amounts to les than the fourth part of the exposure to light required by the'correspond- 'ing material which has been prepared without the anthraquinone-jcompound. I

(4) A diazo photographic printing material is obtained by coating photographic crude paper with a solution containing in 1000 cc. of water Grams 5-hydroxy-2-diazobenzene-l sulfonic acid 20 Tartaric acid 20 Boric acid 10 Resorcine 15 Sodium anthraquinone-2.l-disulfonate 20 (5) A photographic printing foil is produced by saturating a foil oi regenerated cellulose with a solution containing in 1000 cc. of water (6) A photographic crude paper is coated with a solution containing in 1000 cc. of water Zinc chloride double salt of 2.4=-dimethoxybenzene-l-diazonium chloride 12 Sodium anthraquinone-1.5-disulfonate 2 With the help of the photographic printing material thus produced diazotypes may be prepared which are developed in known manner according H to the method of moist developing.

I claim: 1. Light-sensitive material which consists of a carrier having a layer comprising a diazo-com-.

pound of small light-sensitiveness and a sensitizer consisting in an aromatic keto-compound selected from the group consisting of quinones, phenones, acridones and fluorenones.

assess:

2. Light-sensitive material according to claim 1 wherein the said sensitizer i water soluble.

3. Light sensitive material which consists of a carrier having a layer comprising a diazo compound of small light-sensitiveness and as a sensitizer a water soluble,'substantially colorless anthraquinone compound.

4. Light-sensitive material which consists ot'a carrier having a layer comprising a substantially colorless diazo-compound of small light-sensitiveness and a sensitizer consisting in an aromatic keto-compound selected from the group consisting of quinones, phenones, acridones and fluorenones.

5. Light-sensitive material according to claim 4 wherein the said sensitizer is water soluble.

6. Light-sensitive material which consists of a carrier having a layer comprising a substantially colorless diazo compound of small light-sensitiveness and as a sensitizer a water soluble, substantiveness and as a sensitizer a water soluble, substantially colorless anthraquinone compound.

10. Light-sensitivematerial which consists of a carrier having a. layer comprising a substantially colorless diazo phenol alkyl ether of small lightsensitiveness and a sensitizer consisting in an aromatic keto-compound selected from the group consisting of quinones, phenones, acridones and fluorenones.

11. Light-sensitive material according to claim 10 wherein the said sensitizer is water soluble.

l2. Light-sensitive materialwhich consists of a carrier having a layer comprising a substantially colorless diazo phenol alkyl ether of small light-sensitiveness and as a sensitizer a water soluble, substantially colorless anthraquinone compound.

13. light-sensitive material which consists of a carrier having a layer comprising a substantially colorless diazo phenol alkyl ether of small lightsensitiveness and asa sensitizer the 2.7-anthraqu none disulionic acid.

14. Light-sensitive material which consist oi a carrier having a layercomprising a substantially colorless diazo phenol alkyl ether of small lightsensitiveness and as a sensitizer the z-anthraquinone sulfonic acid.

15. Light-sensitive material which consists of a carrier having a layer comprising a substantially colorless diazo phenol alkyl ether of small lightsensitiveness and as a sensitizer the 1.4-dichloroz-anthraquinone sulionic acid. r

GOTILIEB vox POSER. 

